The present invention relates to a display panel using microcapsules which accommodates an electrophoretic or magnetophoretic particles, and more particularly, to a method of producing the display panel capable of arranging the microcapsules at a predetermined position on electrodes accurately and the display panel in which the microcapsules is accurately, arranged at the predetermined position on the electrodes.
In an electrophoretic display apparatus and magnetophoretic display apparatus for displaying a desired picture by using the microcapsules, each sealing colored dispersion media and the electrophoretic particles, the uniform arrangement of the microcapsules over a substrate is important on a stable display operation.
Conventionally, many methods with an object of producing a pressure sensing paper and a heat sensitive paper are proposed as methods of uniformly coating microcapsules on a plane surface.
For instance, the Japanese Patent No. 1545227 discloses a method for producing a pressure sensing copying paper by a free fall vertical curtain method as a preferable method than an air knife or blade coating method.
Also, the Japanese Patent No. 1376224 discloses a hopper typed coating apparatus as a similar method.
Further, the Japanese unexamined patent publication No. 57-27172 discloses a method to spray microcapsules coating liquid to a web (a support body) which runs continuously and to obtain a coating layer of continuous constant thickness by leveling this with a leveling device.
Moreover, the Japanese unexamined patent publication No. 62-138284 discloses a method in which a bonding layer is formed over a substrate, microcapsules layer is formed thereon, and the non-contacted microcapsules with the bonding layer are separated by gravity to form an uniform microcapsules layer of a single layer.
However, the aforementioned methods are for the purpose of obtaining the uniform layer of microcapsules, and are not sufficient methods for forming the microcapsules layer used in the display panel.
Properly placing the microcapsules at positions corresponding to electrodes or magnetic poles, configuring a display pixel in the display panel, is important to display a high definition image with uniform for each pixel. The display panel must form a uniform microcapsules layer and also control an arrangement place of each microcapsules.
Particularly, when trying to display in colors, it is necessary to place a number of microcapsules of different display colors for each pixel and control each individually. To carry out such control, the microcapsules of each display color has to be placed selectively, accurately, and with high precision, the arrangement of the microcapsules must be carried out at a higher precision.
At this point, a method of placing the microcapsules at a desired position selectively and accurately is not proposed in any method as aforementioned, and no such method exists except herein.
An object of the present invention is to provide a method of producing display panel using electrophoretic or magnetophoretic phenomenon, capable of placing microcapsules at the desired positions selectively and accurately.
Another object of the present invention is to provide a method of producing a display panel by using electrophoretic or magnetophoretic phenomenon, capable of high definition display or full color display by placing microcapsules at the desired position selectively and accurately.
Still, another object of the present invention is to provide a display panel using electrophoretic or magnetophoretic phenomenon, in which microcapsules are selectively and accurately placed at the desired positions.
Therefore, a method of producing a display panel according to the present invention, in which microcapsules each sealing dispersion media of each colored to a predetermined color and electrophoretic or magnetophoretic particles are placed over a substrate, and the desired image is displayed by changing a representation color of the microcapsules by applying an electric field or magnetic field to each microcapsules, comprises: a step of coating the microcapsules, each sealing dispersion media of each colored to a predetermined color and an electrophoretic particle or magnetophoretic particle, onto a substrate by using an optical hardening resin as a binder material; a step of fixing the microcapsules at the desired areas onto the substrate on which the microcapsules are arranged by irradiating light beam on the areas to harden the binder material and to fix the microcapsules over the substrate, and; a step of removing the non-use microcapsules and the binder material except for the hardened binder material and microcapsules fixed onto the substrate.
Preferably, electrodes poles or magnetic poles by which an electric field or magnetic field is applied to the microcapsules are provided over the substrate, in the step of fixing the microcapsules onto the substrate, the light beam is selectively irradiated to the areas corresponding to the electrodes or magnetic poles over the substrate to fix the microcapsules to every area corresponding to the electrodes or magnetic poles provided over the substrate.
Further, in the step of the microcapsules fixed over the substrate, the light beam is selectively irradiated at the desired areas by using a photomask.
Specifically, the processes is the steps are sequentially performed on the three types of microcapsules in which the electrophoretic particles or magnetophoretic particles each colored by one of three primary colors, and the dispersion media each colored by a color different to the three primary colors are sealed, and the three types of microcapsules being classified by the colors of the dispersion media, to arrange the three types of microcapsules over the substrate in a predetermined arrangement, to thereby produce the display panel able to display color images.
Further, the processes is the steps are sequentially performed on the three types of microcapsules in which the dispersion media each colored by one of three primary colors, and the electrophoretic particles or magnetophoretic particles each colored by a color different to the three primary colors are sealed, and the three types of microcapsules being classified by the colors of the electrophoretic particles or magnetophoretic particles, to arrange the three types of microcapsules over the substrate in a predetermined arrangement, to thereby produce the display panel able to display color images.
Further, the display panel, according to the present invention, in which microcapsules each sealing dispersion media of each colored to a predetermined color, and electrophoretic particles or magnetophoretic particles, are placed over a substrate, and a display is performed by applying an electric or magnetic field to each microcapsules, to change a presentation color of the microcapsule comprising: a pair of substrates, at least one being a transparent substrate; a plurality of microcapsules placed and fixed between the pair of substrates by an optical hardening resin binder; and electrodes or magnetic poles, provided over the substrate, for applying an electric or magnetic field to the microcapsules.